Sat Dec 12, 2009 11:29 am
The lamp may be approaching time to replace. If the lamp is just on the edge of its functional envelope, under certain circumstances, the ignition circuit will detect the lamp as failed and shut down. Of course that is just a random guess and I would expect the TV to show some kind of error condition (flash lights, etc), not just power off.
Need more details on the exact behavior to do more than take a random guess.
--SS